The engineering and business requirements of navigation by wireless client-server (WCS) navigators, in which route searches and map generation are performed at a central location then transmitted to mobile units, differ somewhat from those of standard standalone navigators. One major difference is that for WCS navigators, data transmission costs are a large part of the ongoing cost of operating the navigation system. In order to economically provide WCS navigation, it is important to minimize the amount of data transmitted while still meeting customers' navigation needs.